Improvement in grinding-mills



'(3. W. LOY 8L F. C. BAKER. `improvement nGrnding-Mills. N0. 129,741'.ZT/gfz Patented July 23] "imsnmi ce Ma/g ATENE EFIO GEORGE w. lLOYAEDERANOIS'O. BAKER, OE JEFFERSON, TEXAS.

IMPROVEMENT IN GRINDING-MILLS.

Specification forming part of Letters Patent No. 129,741, dated July 23,1872.

Spec'ication describing an Improved Grrind-A ing-Mill invented by GEORGEW. Loir and FRANCIS C.` BAKER, of Jefferson, in the county of Marion andState of Texas. l Figure 1 represents a vertical central section of ourimproved mill, the line c c, Fig. 2, indicating the plane of section.Fig. 2 is a horizontal section of the same on the line k 7c, Fig. 1.Fig. 3 is a vertical face view of the upper burr. Fig. 4is a detailvertical section through the lower burr, the curved line c lo, Fig. 2,indicating the plane of section.

Similar letters of reference indicate corresponding parts. j

The invention will rst be fully described and then clearly pointed outin claims.

A in the drawing represents the `spindle of the mill. It is made `in twoor more sections, two, a b, being shown in Fig. 1, there being onesection for every set of burrs. The lower section crests on a step or ina socket of a cross-band. This cross-bar is made vertically adjustablein the frame B of the mill, either by being suspended from or supportedby screws e e, shown by dotted lines in Fig. 1. The upper end of thesection a is squared and enters a socket formed at the lower end of theupper section b of the spindle. This socket is formed in'an enlargement,f, of the section b, which enlargement is rounded at the end, and restsalso on a box that is flttedinto aver- `tically-adjustable cross-bar, g,of the frame.

Screws h, indicated by dotted lines in Fig. 1, regulate the height ofthe section b, which is thus independently adjustable, inorder to ob'-tain the desired space between the upper pair of burrs. G D are theupper and E F the lower pair ofburrs. i The rotary burrs D and F arerespectively mounted upon the sections a and b of the spindle. If morethan two sets of burrs are used, the-spindle is made in as many moresections, each additional upper section having an enlargement'audsocket, f, at the lower end, substantially as shown on section b. Theuppermost burr C admits the grain through its eye from a hopper, G,whose lower part enters the e'ye of (l and iits it nearly air-tight. Theconsequence is that the burrs 1 act as akind of rotary pump, drawing thematerial to be ground down into and between them, thus rapidly`distributing it over the grinding-surfaces.` The grinding-face of theupper burr G, which is shown in Fig. 3, has steps formed on it, whoseinner lines are straight, forming the elbows i, while their outer partsform gentle curves j. The elbows are intended to allow the material tomove away from the eye, so as to reach the grinding-faces rapidly, whilethe curves from the elbows to the verge of the burr prevent the toorapid escape of the material from between the burrs. The pits-in theburrs are intended to presentthe largest possible quantity ofcuting-edges to prevent the too rapid escape of material and obviate thepresentation of too much solid and smooth surface as the burrs wearaway. The rotary burrs have the steps l on their faces made in curvedlines, as shown in Fig. 2, and have pits and cutting-edges substantiallyof the kind above stated for the stationary burrs. The furrows may bestraight or curved, or of any desirable form; but I prefer the form asherein shown. The upper set of burrs C D is inc losed in a case, H, fromthe 'bottom of which a spout, m, extends into or toward the eyeof theburr E. This spout conveys the matter ground by the upper set of burrsto the lower set for regrinding. A similar case, I, embraces the lowerpair of burrs and has a dischargefspout, n. The escape Of matter fromthe hopper G can be controlled by means of slides o o, which extend intothe lower part of the hopper, as shown, and can be drawn in or out atpleasure, to

diminish or enlarge the size of discharge-open ing.

Having thus described our invention, we

claim as new and desire to secure by Letters Patent- 1. The improvedvdress for millstones herein described, consisting of the partiallystraight and curved furrows and intervening lands, stepped or inclined,as shown, and provided with pits orv cells, in the manner and for'thepurpose described and set forth.

2. The spindles A made in connected sections, the upper section b havinganenlarged lower end to be supported on an adjustable cross-head, asspecied.

3. The hopper G, adjustable slides O O,

and stationary burr C, combined, constructed, and arranged substantiallyas set forth.

G. W. LO-Y,

F. C. BAKER.

, Witnesses: Louis B. TODD WM. C. GWYNN.

